PVS-Studio warning V522 for pcsx2

void _SPR1interleave() {
  ...
  u32 *ptag;
  ...
  if (ptag == NULL) {                      <<<---
   SysPrintf("SPR1 Tag BUSERR\n");
   spr1->chcr = ( spr1->chcr & 0xFFFF ) |
                ( (*ptag) & 0xFFFF0000 );  <<<---
   psHu32(DMAC_STAT)|= 1<<15;
   done = 1;
   spr1finished = done;
   return;
  }
  ...
}

This suspicious code was found in pcsx2 project by PVS-Studio static code analyzer.
Warning message is:
V522 Dereferencing of the null pointer 'ptag' might take place. pcsx2 spr.cpp 376

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